Doctor for paper making and like machines



2 Sheets-Sheet l nllll lllll lllll .lll J F. w. VICKERY Filed June 13.

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n IILHL lllllll IlliwlllllllllulllllllllL DOCTOR FOR PAPER MAKING AND LIKE MACHINES a" mu May 9, 1933.

May 9, 1933. F. w. VICKERY DOCTOR FOR PAPER MAKING AND LIKE MACHINES Filed June 13, 1931 2. Sheets-Sheet 2 Fig.4.

I/WEN 7-0;? M Mm 4105666! A/fwwgn Patented May 9, 1933 UNITED STATES PATENT OFFICE FREDERICK WILLIAM VICKERY, or LONDVQNTQENGL-AND, AssIGNoRro VIGKERY mcom'onnrnn, A CORPORATION or MASSACHUSETTS DOCTOR FOR PAPER MAKING AND LIKE MACHINES Application filed June 13, 1931, Serial No. 544,120, and in Great Britain June 26, 1930.

ing movements of the roll, deformations of I the roll or doctor by heating, or wear of the roll, without appreciably changing its angle of inclination to the roll, a matter of particular importance where the blade is set at a steep angle. Another ob ect of the m- Vention is to makethe angle of inclmation of the blade independent of its wear. A further object of the invention is to lessen the likelihood of the blade or itscarrier being set in vibration.

With these objects in view the invention 7 provides for'the blade being borne from the rigid carrier upon supports uny1eld1ng 1n themselves but so yieldably connected with the carrier, as by a pivotal, flexible or merely a loose connection, that they can move slightly at right angles to their plane hinging about the connection to the carrier. The rigid carrier, as usual, is movable under gravity or spring pressure to'press the blade as '1 a whole upon the roll; and the blade and its 7 supports are also movable relatively to the carrier under spring pressure or gravity distributed along the doctor so as to provide for differential movement of parts of the blade 40 as may be required. y f

Thus in one aspect the invention contemplates the combination with the usual rigid carrier loaded by spring pressure or gravlty so as to press towards the roll of a plurality of stiff supports bearing the blade at their ends, so that the several parts of theblade rock, not about the rear edge of the blade but, about an axis at a distance from therear edge, the said supports having the r individual gravity or spring loading to cause each .movements adapting the'blade to slight irregularities of the roll and so forth can be taken care of by allowing yield between to the blade and stiff support.

Viewed from this aspect the invention resides in carrying the blade yieldably in a single stifl support itself yieldably attached to the usual loaded carrier resilient means exerting pressure between the carrier and either the blade or its support to press the blade upon the roll.

In one embodiment of the invention employing a plurality of supports these consistv of a number of stifi fingers fastened to the carrier so that they can rock a little with respect to it at right angles to their plane. The blade is carried in the free ends of these fingers and each finger or each section of the blade is pressed towards the roll preferably by aseparate springacting between the carrier and the finger or blade.

his to be noted that the springs can rock under the influence of their spring or other loading while the doctor is in use; the free dom given to'them is not for the purpose of enabling them merely to be adjustedv once for all with respect to the carrier and then fixed to it.

Examples of this construction are illustrated in the accompanyingdrawings,

Figure 1 being an elevation in section on the line II of Figure 2,

Figure 2 a part plan of one form, Figure 3 a similar sectional elevation of a modification, and

Figure 4 a sectional modification.

In Figures 1 and 2, a part of the usual rigid carrier is indicated at 1, and it is to be clearly understood that this carrier is, as usual, capable of movement, as a rule'by rocking on pivots, under spring action or its own weight for the purpose of pressing elevation of a second length of the fingers and riveted to them,

one end of the'spring forming the hinge connection to the carrier and the other bearing the blade as a whole upon the roll. Upon the carrier are stiff fingers 2 the ends 5 of which abut against a strip 3 screwed to the carrier. The fingers are attached to the carrier by set screws 4 but these pass loosely through the fingers and their heads do not bear on the fingers, so that the latter can rock a little about their ends 5. lhe fingers being-of considerable width and their ends square they cannot rock in their own plane. At their outer ends 6 the fingers carry the blade 7. This may be held'between the fingers and the heads of bolts, which by a shoulder or a distance piece are prevented'from clamping the blade tight. In the construction shown slotted keeps 8 are riveted to the fingers and the rear edge of the blade is engaged in the slot and retained by rivets or other projections 9. A small portion of the roll is indicated at 10 in Figures 1 and 3.

The blade is pressed as a whole upon the I roll by the weight or springs of the carrier 1. To provide for the dilferential movement of one'p'art of the blade with respect to another which is necessary to keep its edgein contact with the roll and which cannot be shared by the rigid carrier,the blade is further pressed upon the roll by pressure distributed over its length and exerted between it and the carrier. This pressure may be exerted by a spring plate, which however is preferably divided into separate springs 11, one for each finger, which are secured to the carrier 1 and bear upon the blade or finger.

Where the doctor is dealing with wet rolls or is subject to large displacements, it is pref- V terposed strip of rubber. Such means may i "so also be provided'to make a water-tight joint between the springs orv fingers.

In lieu'of the loose connection above described the'fingers may be-connected to the carrier by short springs, the ends of the fingers" being preferably rounded and resting against a rounded edge on the carrier; or longsprings may be used extending the whole upon the blade. Alternatively the fingers may be reduced in section,'either in width or thickness orby perforations, at their ends so'as to be springy, and these springy endsv maybe secured in a slot in the carrier or otherwise fastened to 1t.

Thus in Figure 3 the fingers 2 are reduced in thickness at their ends, or preferably at- 'tachedto springs 16 which form the hinge 'connection to the carrier 1.

to facilitate assembly they are fitted with projections 17 which are received in an un- The set screws 4 afford ameans of ad usting the pressure of the several springs.

able bythe'locked set screws 15 I g These springs gers 2, for instance by forming the fingers with an arrow head at their ends. The fingers have a slotted enlargement 20 at their free ends to receive projections on the blade 7 Pressure is exerted as between the carrier 1 and the blade, not only by the weight of the fingers 2, but also by-springs21 which are compressed between the fingers and the lip of the member 19'. These springs 21 may be attached to the fingers in'the same way as the fingers are attached to the carrier,

namely by the engagement of projections in the form of studs 22 in an undercut slot formed in the enlargement 20. Theends of the springs 21 project over the blade? and complete with the enlargement 20 the underout slot in which the projections of "the blade are received; they may also normally exert a' frictional grip on theblade, and in the form shown they permit withelastic resistance some relative movement of the blade 7 and fingers2.

"lVhere a pivotedcarrier is employed the stiff fingers maybe fastened to the carrier so as to pivot co-axially,'0r nearlyso, with it, while the spring plate 'or its equivalent is fastened tothecarrier at a distance from its axis. Figure "4; shows such an arrangement upon a tubular carrier,wh ich, as usual, rocks upon ts ax1s'u'nderspr1ng'0r other loading. The stlfi' fingers 13 surround the carrier and can turn upon it. They carry the blade 7 sub-.

stantially as above described. Springs 14 supplement the weight of the 'finger's *tending to turn them anti clockwise andpressthe blade ontheroll; and their'pressu're' isadjust- I claim: j

'1. A doctor comprising a renewable flexible strip blade, fa rigid carriermovableand loaded to applylthebla'de as a'wholeftothe roll, and stiff, supports individually loaded and movable withrespect to the carrier inter posed between theblade and carrier 2. In a doctor the combination of a carrier, stifl supports rocking upon said: carrier, a flexible blade borne at theend of said supports, means for exerting pressure upon the carrier to forcethe bladetowards 'aroll, and means for exerting "distributed pressure between the carrier and said supports to force the blade towards a roll while allowing dif ferential movement of different elements of theblade. i i

' 3. In a doctor the combination'of arigid carrier loaded to'press towards aroll, a flexible blade, and a plurality of stifl supports interposed between said blade and said carrier and permitting the several elements of the blade to rock about an axis at a distance from the rear edge of the blade, said supports being individually loaded to press the blade upon the roll.

4. In a doctor the combination of a rigid carrier having an undercut slot formed therein, a plurality of stiff fingers having enlargements at one end loosely engaging in said slot, a flexible blade, and means securing said blade in the other ends of said fingers.

5. In a doctor the combination of a rigid carrier, a plurality of still supports yieldably attached at one end to said carrier and having an undercut slot formed therein, a blade attached to the other end of said supports, and springs having enlargements engaging in the undercut slots of said stiflt' supports and compressed between them and the carrier.

6. In a doctor the combination of a rigid carrier loaded to press towards a roll a plurality of stiff fingers, means loosely connecting each of said fingers with said carrier, springs mounted on said carrier bearing on respective fingers, and a flexible blade carried in the ends of said fingers.

7. In a doctor the combination of a rigid carrier loaded to press towards a roll, a stiff support yieldably connected with said carrier, a blade yielda-bly mounted in said support, and means for exerting resilient pressure between said carrier and said blade.

In testimony whereof I have signed my name to this specification.

FREDERICK WILLIAM VICKERY; 

